title: Gender considerations in ventilatory and metabolic development in rats: special emphasis on the critical period.
abstract: In rats, a critical period exists around postnatal day (P) 12-13, when an imbalance between heightened inhibition and suppressed excitation led to a weakened ventilatory and metabolic response to acute hypoxia. An open question was whether the two genders follow the same or different developmental trends throughout the first 3 postnatal weeks and whether the critical period exists in one or both genders. The present large-scale, in-depth ventilatory and metabolic study was undertaken to address this question. Our data indicated that: (1) the ventilatory and metabolic rates in both normoxia and acute hypoxia were comparable between the two genders from P0 to P21; thus, gender was never significant as a main effect; and (2) the age effect was highly significant in all parameters studies for both genders, and both genders exhibited a significantly weakened response to acute hypoxia during the critical period. Thus, the two genders have comparable developmental trends, and the critical period exists in both genders in rats.
authors.affiliation: Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
authors.forename: Qiuli
authors.initials: Q
authors.lastname: Liu
authors.forename: Margaret T T
authors.initials: MT
authors.lastname: Wong-Riley
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001831:Body Temperature; D001835:Body Weight; D002245:Carbon Dioxide / Q000378:metabolism*; D005260:Female; D000860:Hypoxia / Q000503:physiopathology; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015656:Respiratory Mechanics / Q000502:physiology*; D012727:Sex Characteristics; D013990:Tidal Volume / Q000502:physiology
chemical_list: D002245:Carbon Dioxide
keywords: Carbon dioxide production; Gender difference; Hypoxia; Oxygen consumption; Respiration